A model for the genetic modification of wild plant species

Abstract

It is theoretically possible for one subgroup of a population to competitively eliminate another subgroup that has a higher fitness value. To achieve this, multiple homozygous chromosomal translocations and inversions are incorporated into one group, isolating it genetically from the other. Any hybrid of the two isolates is sterile because it is heterozygous many times over with respect to inversions and translocations. This creates an unstable equilibrium in a cross-pollinated species at a gene frequency of pe = wa/(1+wa), where wa is the relative fitness of the less-fit isolate. Any gene frequency not at this equilibrium point tends away from equilibrium and toward a population composed entirely of whichever of the isolates had the favored frequency initially. In a wind-pollinated species, another route is also possible. If a predominantly new-isolate planting were made that was downwind of a pollen and seed barrier, the asymmetrical pollen distribution would slowly, progressively overwhelm wild-type populations located downwind of the new isolate. A seed dispersal system is also necessary, but it need not be asymmetrical or extensive.